Changes and Features in MM 2.4

The following is an overview of the changes and features in MetaModels 2.4, made possible by the “early adopter program” — more information under Fundraising on the MM website.

For a checklist after upgrading to MM 2.4, see further notes below.

Note

To create mm_* tables and attribute columns, a DB migration must be performed — see Schema Manager.
After creating or modifying the labels of models, attributes, or legends, please clear the (translation) cache — see Symfony Translation.

General and Core

With Contao 5, a new version of Symfony comes into play and the minimum PHP version has been set to 8.2. With Contao 5, the most noticeable change is the slightly revised backend with full width and new icons. The new widget width specifications in the input mask such as “w25” or “w66” can of course also be used in MM. MetaModels supports the “Dark Mode” in the backend, including icon variants with the suffix “–dark”.

For custom modifications or programming, several things must be considered that have changed in Contao, such as the deprecations from C 4.13 and C 5, absolute path specifications for files like icons or CSS/JS, or full method call signatures e.g. \Contao\Input::get('myvariable').

For image sizes, various default presets such as “Center-Center” no longer exist — define custom image sizes and adjust them e.g. in the render settings.

Links in the CE and module to model, filter, etc. now open in a separate browser tab.

The MM core now supports a custom “route_prefix”, to call the backend with e.g. admin/ instead of contao/.

Support for Content Security Policy (CSP) has been added for secure JavaScript and inline styles in frontend output — more in the November 2025 newsletter

A link picker for TinyMCE on detail pages can be configured — see jumpTo Picker (Detail Page) for TinyMCE and as dcaPicker.

The “Contao File Usage” extension is supported for searching used files — see File-Usage Integration.

Multilingualism

With MM 2.4, some design principles for multilingualism have been implemented more consistently and corrected — more on the multilingualism architecture in MetaModels

The adjustments include the strict output of fallback language content when the target translation language has no own content — this applies for example also to the File and Content Article attributes.

This behavior can be suspended via the “Disable fallback mode” option — for example, this option is available for the Translated checkbox attribute. This means a value is saved for a language even if it is identical to the fallback value.

When multilingual records are copied, all other languages are now copied in addition to the fallback language.

The backend display of which language is the fallback language has been improved. When switching from the fallback language to the target translation language in the input mask, the attributes now show which content will be output — i.e. whether img_fallback or img_translated .

For translations, a translation tool for DeepL & Co. has been added to complement the XLIFF Export/Import.

Attributes

Checkbox
- Dark mode support for icons — create an additional icon file with the suffix “–dark”
- Template mm_attr_checkbox_icon.html5 for displaying in the backend as ☑ or ☐ in list view
Cowegis Marker (NEW)
- Selection of markers in Cowegis for display on a map — see “Cowegis Layer Integration for Markers”
File
- Template adjustments for output of title, alt, caption from the metafile node
- Two new templates: mm_attr_file_contao_image.html5 for standard output as in Contao, including JSON-LD data output, and mm_attr_file_contao_image_ofpage.html5 for standard output as in Contao where the first image is output as primaryImageOfPage; see also SEO adjustments
Single Select [select]
- Support for use with popup widget in a child table
Content Article
- Support for use in a child table
- Template change — passing an array of content objects
Combined Values
- Option “Always save” (alwaysSave) activated — saves even without value changes
Country
- Country code notation changed to uppercase letters
Long Text
- Migration for basicEntities — see Contao manual
Multi Select [tags]
- Support for use in a child table
Multi-Table (MCW)
- Support for 'inputType' => 'fileTree' with 'multiple' => 'true' including file moving
Text
- Migration for basicEntities — see Contao manual
Token (NEW)
- Generates a cryptographically random, immutable string (token) when a record is first saved — see Token (from MM 2.4)
Translated Alias
- Column langcode changed to varchar(64)
Translated Checkbox
- Dark mode support for icons — create an additional icon file with the suffix “–dark”
- Template mm_attr_translatedcheckbox_icon.html5 for displaying in the backend as ☑ or ☐ in list view
- Column langcode changed to varchar(64)
- Option “Disable fallback mode” for saving a value for a language even if it is identical to the fallback value
Translated File
- Template adjustments for output of title, alt, caption from the metafile node
- Two new templates: mm_attr_file_contao_image.html5 for standard output as in Contao, including JSON-LD data output, and mm_attr_file_contao_image_ofpage.html5 for standard output as in Contao where the first image is output as primaryImageOfPage; see also SEO adjustments
- Column langcode changed to varchar(64)
Translated Content Article
- Support for use in a child table
- Column mm_lang changed to varchar(64)
- Template change — passing an array of content objects
Translated Combined Values
- Option “Always save” (alwaysSave) activated — saves even without value changes
Translated Long Text
- Migration for basicEntities — see Contao manual
- Column langcode changed to varchar(64)
Translated Multi-Table (MCW)
- Support for 'inputType' => 'fileTree' with 'multiple' => 'true' including file moving
- Column langcode changed to varchar(64)
Translated Text Table
- Column langcode changed to varchar(64)
Translated Text
- Migration for basicEntities — see Contao manual
- Column langcode changed to varchar(64)
Translated URL
- Column name changed from language to langcode — migration available
- Column langcode changed to varchar(64)

Filter

All filter rules that generate a URL now have a new setting (“URL type for parameter”) to specify whether parameters should appear as slug or GET parameters in the URL. For backwards compatibility, after an upgrade the setting is “Slug or GET” — this setting is deprecated and should be changed for each corresponding filter rule to either Slug OR GET. More on this in the SEO tips

Simple Lookup
- If the “Static parameter” option is set, a value can now be selected as a preset in both the CE/module MM list and in the MM filter for the filter rule — see Ticket #345
Expression Rule (New)
- With the “Expression” filter rule, the execution of further filter rules can be tied to conditions — see :rel:`rst_cookbook_filter_expression-rule`
Filter-by-related
- Replaces the “Filter-Parent” filter
- The filter rule allows filtering items by properties of a related (relation) MetaModel. A single select (Select) or child table can be used as relations.
Perimeter Search
- The map providers GoogleMaps and OpenStreetMaps now require an HttpClientInterface as parameter
Value from/to for one attribute (from-to)
- Min and max values are available in the template as optionsMin and optionsMax
- New template with type date as mm_filteritem_datepicker.html5
Value from/to for two attributes (range)
- Min and max values are available in the template as optionsMin and optionsMax
- New template with type date as mm_filteritem_datepicker.html5
Full-text search with “Loupe”
- The new filter rule creates an index over selected attributes, which can then be searched — see Loupe
Expression Rule (New)
- Allows the execution of further filter rules to be tied to conditions; more at the Expression filter rule

Frontend Editing (FEE)

Template name change from form_textfield_multiple to form_text_multiple in “FormTextFieldMultipleBundle” (alignment with Contao 5)
In the input mask settings for file upload, the widget modes now only show the relevant settings for single or multiple upload depending on the “Multiple editing” setting — if the attribute setting is changed, the upload must be adjusted accordingly
Customizing the target directory or filename with the insert tag {{post::<attribute-column-name>}} is no longer possible since this tag no longer exists in Contao 5 — a Simple Token can now be used instead as ##post::<attribute-column-name>## — see FEE
Support for multilingual MetaModels — the FE mask has a language switcher like in the BE; see FEE
Form template selection for the input mask (FEE) is now available for all translated attributes
Support for Content Security Policy (CSP)

Known Issues

When toggling to/from debug mode in the BE via the button, the reference page is no longer correct and the page must be navigated to again — e.g. with “back” in the browser and reloading the page
Contao currently provides no way to influence the referer at that point

Checklist for Upgrading to MM 2.4

In general, an upgrade within the MM 2.x branch is straightforward; any necessary label adjustments and DB changes are handled via migrations. However, there are a few things that cannot or can only very difficultly be caught by migrations. For this reason, the following points should be kept in mind when upgrading to MM 2.4:

Please follow all notes from MM 2.3 and MM 2.2
DC_General template changes
Template name change from form_textfield_multiple to form_text_multiple in “FormTextFieldMultipleBundle” (FEE)
Template changes for File and Translated File for metadata output
Check custom programming for Contao 5 compatibility (see above)
For FEE with file upload: check widget mode in attribute settings of the input mask (see above)
For FEE with file upload: check whether insert tag {{post::*}} was used and adjust (see above)
For FEE and the delete item link: consider changes due to CSP support and adjust CSS if needed (see above)
For dark mode: create additional variants of custom icons with suffix “–dark” — e.g. for flag_enabled.svg and flag_disabled.svg create flag_enabled–dark.svg and flag_disabled–dark.svg — see EAP News October II 2024
For the Country attribute, country code notation has been changed to uppercase as in Contao — existing data is adjusted via migration; adjust any custom checks or storage logic
For the Translated URL attribute, the language code column name has been changed to langcode — adjust any custom SQL queries or template outputs
Check image size selections — various default presets such as “Center-Center” no longer exist
If the “Static parameter” option is set in a filter rule, check the default value for “Filter value for attribute” in the MM list — if no items appear in the list, set to “without data value [null]”
For custom queries for perimeter search or geocoordinate lookup, pass an HttpClientInterface as parameter to the map provider
For filter rules, check the “URL type for parameter” setting and set to Slug OR GET
New templates for Content Article (also multilingual) passing an array of content objects
Output of fallback language content when no translated content exists
For the Translated checkbox, set the “Disable fallback mode” option (attribute settings) to keep existing filtering behavior — determine the affected attributes:

SELECT mm.name AS metamodel, a.colname
FROM `tl_metamodel_attribute` AS a
JOIN `tl_metamodel` AS mm ON mm.id = a.pid
WHERE a.type = 'translatedcheckbox'
ORDER BY mm.name, a.colname;